Fix retabbing after iSCSI additions.
* Remove an extra libshare_iscsi_init() in libshare_init().
* Move the check for ZFS_TYPE_VOLUME a little earlier in
  libshare_init(). After we get the dataset, so we don't
  have to call zfs_get_name(zhp) twice, instead use that
  value in the ZFS_TYPE_VOLUME check.
Bump Release.